Control system for target aircraft



Nov. 2, 1948. c. PAULUS ET AL CONTROL SYSTEM FOR TARGET AIRCRAFT FiledJuly 9, 1943 w xm W Z LMU/W PM ,v f

Patented Nov. 2, 1948 G'QNTROL'SYSTEM' FOR TARGET isomer-* Gharles. L;Paulus,.l)ayton, Qhiqs. amiimam. A.-

Application July 9 1943,--'s'eria1%1sfc= rerozr rename .(Cl. 71-450(Grantedjuntler' the; act of Marcus; 1883*, as

amended-April so; 1928.; 370 0. G. 75.7)

The invention described herein may be menu-l factured and used by or forGovernment for goverr'imerrtal 11111130568, without the, payment t9ills,

of royalty thereon.

This invention relates to control. system for aircraft and moreparticularly to acontrol sys}. tem: designed for application to targetaircraftv normally adapted. for remote control by. radio. from. a.controlling airplane.

Target. airplanes, of comparatively small, size and; relativelyinexpensive constructionare commonly employed. in the training of,flying, combat.v

personnel. in target gunnery practice under simulated; aerial combatconditions wherein the target;

airplane is designedtobe remotely-controlled inflightab means of radiocontrol from a control airplaneLso that the targetairplanecan-beutillzed as. a gunnery targetandmaneuvered in. flight,vfor this purposegwithouttheuse of a. human pilot; Insome cases, however,it is. necessary :toemploy ahuman or safety" pilot in the targetairplanejfor.

the. purpose of. checking; the; functioning; of- .the: controls; and,equipment a preliminary to flying the target airplane; without. anyhumanpilot; aboard.

The, situation: of the, human or safety pilot. riding ll'igtha targetairplane is extremely haZa-rdouson;

account of; the fact .that, the operationfof theetar-z. get; airplane.is -underthe controlaof. the TQdiOfSigf nal emanating from thecontrolzairplane and consequently the; safety of the; human;pilot'ridir-ig incthetarget airplane rests; upon the ability of thecontrol pilot to--prop'erly maneuver; the target; airplane from-his.remote position to speedilyrcope withhazardous conditions: suddenly"encountered: bythe-tareetairp1ane In: theslightof the foregoing theprimarysobj ectof;-the-invention;is tQQPIQl/idBQQ control systemic-r:

the target airplane which will enable the hull'i-al'1 pilot.riding-.therei1r tOoVerIpoWer-or limit the e'fiect of; the; remote; or-- radio:control uponthe v target; airplane-..

It; is; a further object of: the invention to pro vide: a control: meansfor: targetaircraft wherein therremote: controlzmeans may be instantly'over poweredg-bythe humanpilot and yet-wherelnthe remote; control meansis capable of immediate automatic restoration to its: original:controlling status-upon. re'linqui'shment of-"ma'nuai control bytho-humanapilot riding: in thetarget airplane:

Toward: 'the accomplishment of the foregoingobjects;.the inventioncontemplates the provision= 0f:131 d11ai11 control system comprisinga'plurality of separately; operable controlmeans; each' of whichcontrohmeans: is associated. with a controllable memberior actuationthereof,- and overpower" means interposedi between one of said-controlmeans;;and: said: controllable means; said}- over-'- power; meanszbeing;operative-to permit actuation;

of? tha controllable; means? independently ofsa'id- 2 one. of.said-control meansgupon .oiieratidnofthe. otli'e'l idfisdidldfitldlFfilrlsL p Z 'Illi; overpower fii'alfi's'l. constitutes. a.fieilible'; or yiefldable force transmitting. iean's designed parti'ciulfarly to he: incorhofatfed in the; control system of a. target.airplane such asma b'I emploYedior controlling. the actuationtg one ofthe. control surfaces of such" ai plane, For thlszpilrpose', theinvention conten'iplatles"- the. provision of a dualcontrol systeminclllding' a r'adio'or refii ote com trol means associated with-thecontrol surface for].

normally controlling. actuation. thereof and a separate manual. controlmeans. associated with saidcontrol. surface. for alt'erhat'ivelycontrolling} actuation. thereoli, In such a. dualantra system} theyinvention contemplates .the'interpositi'on of,-

facejindependently of: the operation. of the.- radio.

tionDr ceedsincO uniotior'iLwlthitlieaccdmpanya in'g arawines inwfiicn rV I Figure," l. is an; isometricschematic; view illus:

trailin thei'livefition. asljaoplie'd' tol'al control SyS-- '1 tern? forone. of thiefcontrol surfaces of. a. targetiairf- 1 121118.; r r vFiguIe'lZ'is along'itudinallsectional view through theoverpqwer'device'orthe invention. A

Figure Bils'f a: transverse; sectional view, through said overpowerdevice'..talten' on the line. 3-3/ of. Figure2;,looking.inthedirectlondf 'the arrows; Now, referring? to. the drawings. for a; detailed;description of" the; invention, the. numeral I generally designateszelnlautomatic'or'radio controlled} pilO't' means? ,Whlbh? isjadapted;through; inter,

mediateactuatin itiieahsito controlfthe operationofagcontrol'lablejmea'ns.adapted'toaffecttheflight:

operation of 'theitalfget airplane;- s-iich" controllable.

means; for instance, including; the; control: surfaces'of. the airplane'sucli.asf}the.elev'ator,ailerons; rudder, an'd'wing ffiap's. Iii'ltheembodiment oithe invention-illu trated;tiie'radio. or'freriiotecbnti'olmeans. I i is admitted. to, effect. the" operation; of the: elevator 2through the intermediary: of mechania:

calactuating rfieansliorftheelevator};. The actiu,

ciated with and directly controlled by the radio V or remote-controlmeans I, the piston or plunger 8 of the servomotor 1 being associatedthrough an adjustable link 9 with an overpower device generallydesignated l6 which in turn is pivotally i members 23 and 24 when thelatter are asseni bled on the rod 2 I withinthe housing in conjunctionwith the spring 22 under compression.

' A pivot bracket 29 is provided on the housing 20 fixed thereto andincludes the trunnions and 30a respectively adapted for cooperation withsuitable pivot openings provided in the respective forked portions ofthe bracket H fixed to the opcrating shaft 6 as aforesaid. Theadjustable connected to a forked bracket I1 I rigidly fixed to theoperating shaft 6.

Separately and alternatively operable control means, operable separatefrom the radio or remote-controlmeans l is'also provided for effectingrotation of the operatingshaft" 6 for actuation of the'elevator 2; Saidseparately operable control means comprises a manual control leveror joystick l2 fixed to a shaft l3 rotatably supported with respect to theairplane. 'Ihe shaft 13 has rigidly'fixed thereto a horn or lever M towhich is pivotally connected one end of a link I 5, the other end ofwhich link it is pivotally connected to a homer lever 16 rigidly fixedto the operating shaft 6.

The'overpower means generally indicated by the numeral it constitutes ayieldable force transmitting means capable of permitting actuation ofthe elevator 2 by the manual control lever 12 independently of, andwhile the elevator 2 is generally under thecontrol of, the automatic orradio control means I; as will be'more fully'unders'to'od from thefollowing-more detailed description of said overpower means lil Nowreferring to Figure 2, the overpower means it) comprises a reactionmember constituting a cylindrical housing or sleeve 29,2. forcetransmitting member comprising the shaft or rod Ziyandyieldable meansinterposed between the reaction member and the force transmittingmember. V V

In theembodimentshown saidyieldable means comprises a coiled spring 22through which the rod or shaft 2| extends axially thereof; One end ofthe spring 22 bears against the floating abutment member 23 which isloosely mounted on the shaft 2lfor'long'itudinal or axial movementrelative thereto and the other end of said spring22 bearsagainst asimilar floating abutment member 24 likewise loosely mounted on shaft 2!for longitudinalor axial movement relative thereto, The

rings 25 and 25 respectively engage the annular shoulders 23c andZaofth-e abutment members 23 and 24 when the latter are assembled withinthe housing 20 in conjunction with the spring 22 under compression.Fixed abutment members 21., and 28 are adapted to be fixed on the rod 2!the abutment 'member2? being pinned to said rod and abutment member 28being threaded for cooperation with the threaded portion Zia of therod2l and likewise being adapted to be pinned maxed position withrespect to said rod. Each of the fixed abutment members 21 and 28 isadapted to engage one of the respective floating abutment link 9 isswivelly connected to the rod 2| and internally threaded for cooperationwith the threaded portion 8a of .the plunger or piston 8 of theservocylinderl. The servo cylinder 1 is pivoted as at 35 to a suitablebracket 36 rigidly fixed to the airplane generally designated by thenumeral 31." f

In the operation of the control system illustrated in Figure 1, theactuationof the elevator 2, or other airplane control surface, isadapted to be normally controlled by the radio or remotecontrol means iassociated with and effecting operation of the servomotor 1. Movement ofthe plunger or piston 8 of the servomotor I normally causescorresponding movement of the overpower unit I!) and consequent rotationof the operating shaft 6, the spring 22 being designed to resistmovement of the rod 2! relative to the housing 20 under the conditionsof normal forces required to be exerted by theservomotor I for actuationof the control surface 2 through the intermediate actuating means.When,however, a'situation exists requiring that the human pilot ridingin the target airplane take over manual control of the control surface2, the human pilot may do so through manipulation of the manual controllever 12. Under such condition, actuation of the manual control lever l2will serve to rotate the oper-' ating shaft 6 for actuation of thecontrol-surface 2 and the force exerted in rotation of the operatingshaft 6 by the manual control means will serve to cause movement'of thereaction member ortive or neutral position, and, thus, movement of thepiston and rod 8 is not possible under manual actuation of shaft 6through manual control member-J2. 3 1

Thus it will be seen that if the'm'anip'ulation of the manual controllever 12 is such asto rotate the operating shaft 6 in a clockwisedirection, havingreference to Figure 1, the reaction-memher or sleeve2ilwill becaused to move in a leftward direction. (Figure 2) relativeto.the rod 2 I, the fixed abutment member 21, and the fioating abutmentv member 23 engaged therewith.

Such leftward movement of the member 20'wiIl cause leftward movement of.the floatin abutment member 24 relative to rod. 2|, thereby compressingthe spring 22 between the floating abutmentxmembers 23, and 24.Similarly when the manual control lever 12 is manipulated vso-as torotate the shaft 6 in a counterclockwise direction, having reference toFigure l, the reaction member or sleeve2ll will be caused to be movedin' a rightward direction (Figure 2) relative to the rod 2|, thefixedabutment member 28, and floating abutment member 24 engaged therewith,Such rightwardmovement of the member, 29 will cause rightward movementof the floating abutment member 23 relative to the rod 21, therebycompressing the spring 22 between the floating abutment members 23 and2%.

It will, therefore, be seen that, under any condition of manipulation ofthe manual control lever l2, the reaction member or sleeve 20 will becaused to be moved relatively to the force transmitting member or rod 2!against the action of the spring 22. Consequently the overpower means I0provides a flexible or yieldable force transmitting means capable oftransmitting the required force from the servomotor to the controlsurface 2 for actuation of the latter, thus permitting actuation of thecontrol surface 2 by operation of the servomotor 1 under control of theradio or remotecontrol means 1, under normal conditions, and. saidoverpower device 1 0 is also capable of permitting the manual controlmeans to limit or overpower the automatic radio or remote-control meansthrough the relative motion of the housing 20 and rod 2! against theaction of the spring 22 and thus effect actuation of the control surface2, by operation of the manual control lever i 2, independently ofoperation of the servomotor l and radio or remote-control means i. Itwill be apparent, of course, that, on account of the interposition ofthe overpower means or yieldable force transmitting means between theradio or remote-control means I and the control surface 2, the operationof the manual control means 12 will not adversely affect theoperativeness of the radio or remote-control means or the intermediateoperating parts.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent of the United States is:

1. In a system for controlling an aircraft in flight, in combination, anaircraft control surface, actuating means therefor, servo-operatingmeans associated with said actuating means, remote control means forcontrolling operation of said servo means, yieldable force transmittingmeans interposed between portions of the actuating means intermediatesaid servo means andsaid aircraft control surface, and. manual controlmeans directly connected with said aircraft control surface foractuation thereof independently of said servo means, said yieldableforce transmitting means being normally operative to transmitcontrolling force from said servo means through said actuating means tosaid aircraft control surface for actuation of the latter, and saidyieldable force transmitting means being yieldable to permit relativemovement between said portions of the actuating means intermediate saidaircraft control member whenever said manual control means is actuated.

2. In a system for controlling an aircraft in flight, in combination, anaircraft control surface, actuating means therefor, servo meansassociated with said actuating means for operating the lat ter, remotecontrol means for controlling operation of said servo means, manualcontrol means connected to said actuating means for alternativelycontrolling actuation thereof, and yieldable force transmitting meansinterposed between portions of said actuating means intermediate saidservo means and the point of connection of the manual control means withsaid actuating means, said yieldable force transmitting means beingnormally operative to transmit control force from said remote controlmeans through said actuating means to said aircraft control surface foractuation of the latter, and said yieldable force transmitting meansbeing yieldable to permit relative movement between said portions of theactuating means intermediate said servo means and the point ofconnection of said manual control means with said actuating meanswhenever said manual control means is actuated.

3. In a system for controlling an aircraft in flight, in combinationwith an aircraft control surface, actuating means therefor, servooperating means associated with said actuating means, remote controlmeans for controlling operation of said servo means, yieldable forcetransmitting means interposed between portions of the actuating meansintermediate said servo means and said control surface, and manualcontrol means directly connected with said aircraft control sur face foractuation thereof independently of said servo means, said yieldableforce transmitting means being normally operative to transmitcontrolling force from said servo means through said actuating means tosaid aircraft control surface for actuation of the latter, saidyieldable force transmitting means being yieldable to permit relativemovement between said portions of the actuating means intermediate theaircraft control surface whenever said manual control means is actuatedand comprising a sleeve member secured to one of said portions, a rodmember secured to the other portion and extending axially through thesleeve member and axially movable relative thereto, a pair of springseat members movably mounted upon said rod for axial movement relativethereto and disposed Within the sleeve member, a compression springdisposed on the rod with its opposite ends bearing on the spring seatmembers to urge the spring seat members apart in opposite directionsrelative to the rod, a, removable snap ring abutment member seated in anannular groove formed in the interior of the sleeve memher at each end,forming opposing abutment means limiting the movement of the spring seatmembers within the-sleeve member away from each other under theinfluence of the compression spring member, and spaced abutment memberssecured on the rod with the spring seat members and the compressionspring therebetween, each rod carried abutment member being disposed incontact with one of the spring seat members when the spring seat membersare disposed in contacting engagement with the snap ring abutmentmember.

CHARLES L. PAULUS. HOWARD A. KLEIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Date Great Britain 1910Number Number

